Edexcel GCSE Computer Science (1CP2) Exam Questions

• A Address bus (1)
• The only correct answer is A. The correct answer is address bus. Do not accept 'address' on its own.
• B is not correct because the control bus carries control signals in both directions between the CPU and other components
• C is not correct because the data bus carries data in both directions between the CPU and main memory
• D is not correct because the system bus is the collection of all three buses

Award up to two marks for a linked explanation such as:

• (The ECU) is more reliable/less likely to crash (1) because it only runs the one program/has a single purpose (1)
• (The ECU) cannot be affected by other software/viruses (1) because it cannot run other software/it can only run the program it was made for (1)
• (The ECU) is cheaper (1) because it has limited processing resources/less memory/simple components (1)
• (The ECU) uses less power (1) because it has limited processing resources/a simpler processor (1)
• (The ECU) is smaller (1) because it has fewer components/less memory than a general purpose computer (1)

For both marks, the expansion must follow/associate with the statement.

A suitable benefit stated on its own earns one mark.

Do not accept a description or a location given as the reason, e.g. 'because it is part of the car', 'because it is inside the engine', 'because it is embedded'.

Do not accept a description of an embedded system on its own as the benefit, e.g. 'it does one specific job' or 'it is part of the car'.

Do not accept 'it is faster'/'it has a more powerful processor' as embedded systems have limited processing resources.

Award up to two marks for a linked explanation such as:

• The read/write head moves over the surface of the platter (1) and detects whether each area of the disk is magnetised (1)
• The platter spins/rotates (1) so the read/write head can pass over the whole surface/tracks of the disk (1)
• The pattern of magnetised and non-magnetised areas detected by the read/write head (1) is read as binary 1s and 0s (1)
• The drive head detects the direction of magnetisation of each area (1) so the data can be read as binary (1)

For both marks, the expansion must follow/associate with the statement.

Allow one mark for stating that data is read magnetically / that the read/write head detects the magnetisation of the disk without a linked reason.

Do not accept answers that describe how data is written to the disk, such as the head magnetising the platter, rather than how it is read.

Do not accept 'a laser reads the pits and lands' - this describes optical storage, not magnetic storage.